I thought I would open a new thread for discussion of Axiom subwoofers in general, and the development of the next generation in particular. With all that has been learned during the design and engineering of the new amplifier line, it has naturally lead us towards looking at our subwoofer amplifier platforms to see what improvements might be possible. To do this is going to require a better understand of how you are using your subwoofers, and with what types of partnering equipment. So, I'd like to start off with a serious of questions which I'm hoping everyone will answer and share with us and the group. You never know, your answers to these questions might allow us to make some significant improvements to the future Axiom subwoofer line-up!

Now, on to the questions:

What Axiom subwoofer(s) do you own?

Yamaha YST-SW315

Where do you have the Level, Frequency, Phase, and Subsonic Filter (if applicable) controls set?

The only signal setting is the Level control, it's set to 1/3 on both. No cross-over, no phase (I really like this, as those controls are in most modern receivers, and there's no reason to duplicate them in the sub with analog controls.)

The only input is RCA. The RCA output is buffered, and not just an internal Y, so there's no level loss when daisy chaining (but at the same time, downstream devices, like my Buttkicker, don't get a signal when the sub is off).

Pioneer VSX-1018AH receiver.

Axiom M22 mains.

The crossover is set to 80 Hz. The trim level for the mains is -0.5 dB and sub is +2.0 dB. These were auto configured.

The RCA output is buffered, and not just an internal Y, so there's no level loss when daisy chaining

I hadn't heard of this, but I like it.

Along the same lines, I was thinking it would be cool to have a device that takes a receiver's sub output and splits it up to maybe six ways (for my own purposes, that's four subs plus two Buttkicker amps), but also allows you to set the levels independently of each other. Avoiding daisy-chaining and level loss, along with independent level calibration, among that many LFE-producing units would be my ideal.

Along the same lines, I was thinking it would be cool to have a device that takes a receiver's sub output and splits it up to maybe six ways (for my own purposes, that's four subs plus two Buttkicker amps), but also allows you to set the levels independently of each other. Avoiding daisy-chaining and level loss, along with independent level calibration, among that many LFE-producing units would be my ideal.

It probably goes without saying, but if someone made a device like this, you'd want a remote control. For calibration purposes, you'd have the level controls for each individual unit, and for general use, you'd have the master volume level. While you could still take care of that one in the receiver, it might be easier to do on this remote.

This might be slightly off-topic here, but since we're talking subs, this might helpful to some who have trouble with sub hum.

I was able to largely quell my 2 X Velo subs' hum (I suspect was from my cable TV feed) by grounding the outside barrel of one of each sub's unused RCA jacks to the 3rd prong of the house power supply. It worked only if the plug in the wall socket was positioned 'just right'. If it was disturbed at all, the hum returned.

How are you connecting your signal source to the subwoofer (RCA/XLR/High Level)?

RCA

What receiver/processor/pre-amp/integrated amplifier are you using?

Denon 4802

What are you using for your main speakers?

LFRs and VP180

Where do you have the crossover frequency and trim levels set in your processor/receiver for your main speakers and your Axiom subwoofer?

THX (80 Hz) but with fronts (L/C/R) set to Large

Are you using the trigger on your subwoofer?

Yes it has an automatic trigger that turns it on when a signal is detected on the RCA. This is set at "Low"

Just a quick update on this: I've been tweaking my setup to get the best results with the LFR's now in my system (no DSP upgrade yet). I tried a somewhat unconventional approach to help my not so great sub extend the already low range of the LFR's using the killer LFE track on the "Master and Commander" DVD which has good content down to well below 20 Hz.

I realized that setting the sub's low pass filter as low as it can go - labelled 40 Hz - might help to focus all its amp power on the really low stuff. This way I can also bump up the volume without impacting music content.

This seems to have worked as with the sub on I can definitely hear and feel some low rumbles in the cannon battle scenes that aren't there without the sub (and didn't seem noticeable before my changes).

The subs I had to turn up the gain on the back almost half way to get Audyssey to hear anything from them. I settle on +2.5 for each sub individually when I ran Audyssey then with both plugged in and running Audyssey it set them to -.5 which I then upped by 2db to +1.5